Description

Application Scenarios

A combined-cycle power block running GE Mark VIe turbine controls is the natural home for the IS220PHRAH1A. On a TMR configuration, three packs — one on the R, S, and T control branches — plug into a common IS200SHRAH2A-style analog terminal board, each feeding ten field transmitters (suction and discharge pressure, lube-oil and seal-gas pressure, cooling-water temperature loops) and two 4–20 mA outputs driving electro-pneumatic positioners on governor and IGV control valves. Before the HART-enabled pack generation, those smart transmitters and positioners reported only their analog 4–20 mA value into the Mark VIe, with device diagnostics trapped in hand-held communicators carried by the instrument technician. With the IS220PHRAH1A in place, the same two wires now carry the analog control signal and the overlaid HART digital layer, so a valve positioner that is drifting toward a packing failure, or a transmitter whose diaphragm is starting to slug, flags itself to the AMS workstation days before it becomes an operational excursion. The same pack is equally at home on gas-turbine skids, steam-turbine BOP cabinets, and compressed-air or fuel-gas metering stations wherever the IS220PHRAH1A serves as the catalog-matched interface between the Mark VIe controller and the smart instrumentation layer.worldofcontrols.com+2

4. Parameter

Parameter	Value / Description
Product Model	IS220PHRAH1A
Manufacturer	GE (Emerson) — Mark VIe Speedtronic family
Product Category	HART-Enabled Analog Input/Output Pack
Functional Acronym	PHRA — Revision A
Channel Count	12 per terminal board (10 AI + 2 AO)
Analog Inputs (AI)	10 total — first 8 configurable as ±5 V or 4–20 mA; last 2 configurable as +1 mA or 4–20 mA
Analog Outputs (AO)	2 × 0–20 mA / 4–20 mA current loop, 800 Ω max load
A/D / D/A Resolution	16-bit analog-to-digital converter; 14-bit digital-to-analog converter
Scan Time	5 ms (200 Hz normal scan)
Common-Mode Rejection	60 dB AC @ 60 Hz; 80 dB DC; common-mode voltage range ±5 V
HART Support	Native HART pass-through on AI and AO channels, relaying to Asset Management System (AMS)
Network Communication	Dual 10/100BaseTX Ethernet (IONet), RJ-45 connectors, full-duplex point-to-point
Input Power	28 VDC nominal, 3-pin connector, soft-start inrush control
Terminal-Board Interface	DC-62 pin connector, direct plug to SHRAH-family analog terminal boards
Dimensions / Operating Temp.	8.26 cm H × 4.19 cm W × 12.1 cm D; –30 °C to +65 °C (–22 °F to +149 °F)
System Grouping / Origin	Mark VIe/S Series Group One; Country of origin United States; Manual GEH-6721

The native HART pass-through is the parameter that distinguishes the IS220PHRAH1A from the non-HART analog pack — it means the same two-wire loop that delivers 4–20 mA control also carries device diagnostics, second process variables, and calibration history into the Mark VIe without a second field cable.worldofcontrols.com+1

5. Technical Principles and Innovative Values

Innovation Point 1 — Distributed I/O with local processing and 1 ms SOE time-stamping. Each IS220PHRAH1A contains its own processor board plus acquisition board, so analog scaling, filtering, and voting happen at the pack rather than in the central controller. Because the pack is DIN/terminal-board mounted and DIN-rail wiring eliminates marshalling, a single Mark VIe controller supports up to six simplex packs over IONet with a minimum 20 ms frame period — a compact architecture that removes the dedicated I/O chassis that older Mark VI installations required.colletplc.com+1
Innovation Point 2 — Native HART pass-through in the analog loop. In 4–20 mA mode the IS220PHRAH1A relays HART messages between field devices and the Asset Management System bidirectionally, so a valve positioner reports actual travel and air pressure over the digital layer while the analog signal performs control. This is the feature that removes the routine manual field inspection of smart instrumentation — the device is effectively online to the AMS for its entire service life.worldofcontrols.com
Innovation Point 3 — Mixed-signal flexibility on one catalog number. The first eight inputs accept either ±5 V voltage or 4–20 mA current-loop signals, and the last two accept either +1 mA or 4–20 mA, with load-termination resistors located on the terminal board so the pack senses voltage directly. Combined with two 0–20 mA outputs rated to 800 Ω, one IS220PHRAH1A covers voltage, current, loop-powered, and externally powered field devices in the same terminal block — reducing panel SKU count versus dedicated voltage-only or current-only packs.worldofcontrols.com
Innovation Point 4 — Simplex and TMR mount on the same terminal board. The pack plugs directly onto the analog terminal board through a DC-62 connector and threaded-stud mounting bracket, with one IS220PHRAH1A per terminal board in simplex and three packs in TMR voting at the pack level. Because I/O redundancy is a single selection during hardware configuration and transparent to the application code, a TMR upgrade does not require re-engineering the control logic — a decisive advantage when migrating a critical turbine train from simplex to triple-redundant.colletplc.com
Innovation Point 5 — Built-in diagnostics with front-panel LEDs and soft-start power. Visual diagnostic LEDs provide immediate at-a-glance pack health, the soft-start circuit controls inrush current on power application so the pack can be plugged into a live 28 VDC feed without pre-powering the cable, and dual RJ-45 IONet ports give a redundant network path where the standard practice connects ENET1 to the R controller network. These are the operational details that turn a fault call into a five-minute verification rather than a half-day diagnostic.